onifconsole prevent shutdown on mbr 2013

[Jilles Tjoelker]

On Sat, Jun 14, 2014 at 07:58:17AM +0800, Huang Wen Hui wrote:
> I notice onifconsole is enable on STABLE recently, In mbr 2013 there is an
> uart port, it may not useful:

> uart0: <8250 or 16450 or compatible> at port 0x3f8-0x3ff irq 4 flags 0x10
> on isa0
> uart0: console (338,n,8,1)

> If onifconsole is enable, "shutdown -p now"  or press power button on
> keyboard is not properly work.
> system still can ssh.

> Before shutdown command, ps -ax show:
> [snip]
> After showdown command, ps -ax show:
>  PID TT  STAT    TIME COMMAND
>    0  -  DLs  0:00.10 [kernel]
>    1  -  SLs  0:00.02 /sbin/init -s
> [snip]
> 1693 v0- Z+   0:00.01 <defunct>
> 1694 v1- Z+   0:00.00 <defunct>
> 1695 v2- Z+   0:00.01 <defunct>
> 1696 v3- Z+   0:00.01 <defunct>
> 1697 v4- Z+   0:00.01 <defunct>
> 1698 v5- Z+   0:00.01 <defunct>
> 1699 v6- Z+   0:00.01 <defunct>
> 1700 v7- Z+   0:00.00 <defunct>
> 1701 u0- Z+   0:00.01 <defunct>
> 1747  0  Ss   0:00.01 -csh (csh)
> 1780  0  R+   0:00.00 ps -ax

> All getty processes become to defunct.

Please provide the output of
  procstat -k 1
during the hang (after the shutdown command).

If you are running stable/10, reverting r261997 (an MFC of r259441)
might help. In some circumstances, r261997 makes a process unkillable
while waiting for output to drain while closing a tty.

-- 
Jilles Tjoelker